Lifesensors demonstrated the feasibility of an implantable telemetric intracranial pressure (TICP) sensor in dogs for 14 weeks. The TICP sensor provides the ICP value and wave form in real time, is accurate over a clinically significant range of 0-90 mm Hg, and has insignificant transducer offset (<5 mm Hg during weeks 8-14)when compared to ventricular fluid pressure. We now propose a short-term study (< 29 days) of the TICP sensor in 10 human subjects to assess the feasibility of surgical implantation and evaluate its accuracy. We will assess the mechanical stability of a mounting collar and the effect of TICP sensor coplanarity on accuracy. We will determine whether accurate TICP measurement can be obtained with epidural placement of the TICP sensor. Static (drift) and dynamic (beat-to- beat response) changes in TICP will be compared to standard ICP measurements. If proven feasible, the TICP sensor is potentially a major clinical advancement in ICP monitoring because it would be implanted for long durations and could be used in practice settings outside an intensive care unit where it would provide previously unavailable and clinically valuable low cost information regarding ICP in diseases affecting thousands of patients annually. PROPOSED COMMERCIAL APPLICATION: lntracranial pressure (ICP) is an important physiologic variable affecting patient outcome in many diseases. Our sensor eliminates limitations associated with existing ICP monitoring devices. Commercialization will improve clinical practice of TCP monitoring and enhance development of therapies for disorders comprising over 250,000 patients annually,including hydrocephalus, intracerebral hemorrhage, traumatic brain injury, ischemic stroke, brain tumor or fulminant encephalopathy.